A fire extinguisher is an important part of a home for safety purposes given the number of ways that a fire can start. The problem is that there isn’t one type of fire nor is there only one kind of fire extinguisher to do the job.
I bought a small fire extinguisher when I purchased a condo many years ago but didn’t pay any attention at the time to what I was buying. I just bought a fire extinguisher that would fit in the closet in the kitchen, just in case! So I thought I’d do some research to learn more about fire extinguishers including what types exist, when you use them and how frequently they have to be replaced or refilled. Here’s what I found.
While they don’t have an actual expiry date, a disposable fire extinguisher may last up to 12 years whereas a rechargeable one should be recharged every 10 years or according to need. A fire extinguisher’s manufacture date is shown on the label so you can count forward to determine its latest replacement date.
Even if it’s not being used, a fire extinguisher loses its charge and should be recharged if possible or replaced. Let’s take a closer look at aspects of fire extinguishers you should be aware of because as we’ll see below it isn’t black or white.
Why do fire extinguishers expire?
A fire extinguisher will lose its charge over time even if it is never used. Rather than concerning ourselves with the expiry date of the product as being a hard and fast rule, we need to instead replace a fire extinguisher on need and when required.
A fire extinguisher will lose its ability to stop a fire over time due to age. Most commonly, fire extinguishers lose their charge because:
- The seal on the fire extinguisher deteriorates or weakens and gas is allowed to escape.
- A valve may be damaged or a valve component like a valve stem may be the problem.
- The actual fire extinguisher cylinder may have a small puncture or other damage.
- The fire fighting material inside the tank can harden over time and become unusable, in the case of some Class ABC (more on that below) models.
Material may leak out of the unit for a number of different reasons that end up rendering the unit useless in a fire even if is less than 10 years old. So if you happen to recharge a fire extinguisher that is leaking, you’re going to be back in the same position in the near future.
Do expired fire extinguishers still work?
It might work but do you want to take that chance? A fire extinguisher is of course something that you hope you will never use. But if you need to use it, you want to make sure it works immediately.
The problem is that you won’t know that it doesn’t work properly until you need it. This is why it’s more important to monitor the fire extinguisher itself, its pressure gauge and to inspect it for noticeable damage that may indicate it needs to be replaced.
At some point, a fire extinguisher simply no longer has enough pressure to work properly when needed. In that regard, you should replace – or at least buy an additional – fire extinguisher at the appropriate time.
Fire extinguisher design
Fire extinguishers are of two main designs:
One-time use: These are non-rechargeable fire extinguishers that are designed to be used once and then replaced. Don’t test them by using it because you drain some of the contents which makes it less effective during an actual fire.
Rechargeable: These fire extinguishers can be recharged as needed by a certified fire equipment dealer. Refer to your owner’s manual to confirm the recharge date.
Parts of a fire extinguisher
The main components of a fire extinguisher are:
- Cylindrical tank that holds the extinguishing agent and is a pressurized canister
- Carrying handle
- Operating lever to discharge the extinguishing agent during a fire
- Safety pin which gets removed during use and to prevent accidental discharge
- Pressure gauge to monitor the level of the extinguishing agent
- Hose to aim at the fire and discharge the extinguishing agent upon depressing the operating lever
Fire extinguisher types and classifications
Fire extinguishers are rated and classified based on what type of fire(s) they are capable of handling and the type of burning material(s) they can extinguish. They are given a letter classification based on the following:
Class A
Used on solid combustible materials like wood, paper, textiles and rubbish. Tends to be used in homes and businesses.
Class A fire extinguishers have a number in front of them which denotes its effectiveness compared to 1.25 gallons of water. So a 3A fire extinguisher would be like using 3.75 gallons of water on a fire.
Class B
Used on flammable liquids like grease, gas, oil and oil-based paints. Tends to be used in homes and businesses. Class B fires involving flammable liquids are particularly dangerous given the risk of explosion.
Class B fire extinguishers are rated differently from Class A ones. For Class B products the number in front of the letter B represents the number of feet of coverage the canister can provide if using the recommended sweeping back and forth motion. So if you see a fire extinguisher rated 20B, that means 20′ of spray can be produced to give you an idea of how big a fire you can deal with.
Class C
Used on electrical equipment such as appliances, tools, electrical panels, wiring, computers and anything that is plugged which increases the risk of electrocution and prevents water-only from being used. Tends to be used in homes and businesses.
There is no other rating system for Class C as there is for Class A and B. A Class C extinguisher is designed to deal with a fire involving electricity.
Class D
Used on combustible metals like magnesium, aluminum, etc. Tends to be used in factories.
There is no other rating system for Class D as there is for Class A and B.
Class K
Used on combustible cooking media such as cooking oils, animals fats and vegetable oils. Tends to be found in commercial kitchens, restaurants, cafeterias, caterers, etc.
You will also find multipurpose fire extinguishers such as BC and ABC that are commonly used around the home so that they are available to tackle more than one type of fire.
There is no other rating system for Class K as there is for Class A and B.
Best fire extinguisher for home use
Fire extinguishers for home use generally fall into the following categories:
Water fire extinguisher
Water fire extinguishers are used on Class A solid combustible fires such as wood, paper, textiles and rubbish. This is a possible option for a home office if a fire extinguisher may be required. Water-only fire extinguishers cannot be used on electrical fires as the water conducts electricity and you can be electrocuted.
The other problem with water fire extinguishers is since there are no chemicals and contains water only, they are very heavy due to their lack of firefighting abilities. Thus water fire extinguishers have a low firefighting rating.
Some newer water-based fire extinguishers have additives to make them lighter weight and others have an additive that makes them safe if you accidentally use them on electricity.
Foam fire extinguisher
Foam fire extinguishers are highly effective on Class A and B fires. They are also referred to as Aqueous Film Forming Foam (AFFF) fire extinguishers. They cover the fire with foam effectively starving it of oxygen and help to prevent re-ignition of the fire. They are good for porous materials and are also suitable for flammable liquids.
Dry powder fire extinguisher
ABC Powder fire extinguishers are effective on class A, B, C and electrical fires so they are quite versatile in that regard. While ABC powder fire extinguishers have a high fire rating, they don’t have a great cooling effect on fires so the risk for the fire to re-ignite exists.
Care should be taken when using dry powder fire extinguishers indoors and should be avoided in small rooms given that you may inhale powder while using it. They are also messy to clean up.
Class BC fire extinguishers are not suitable for home use since they are generally not good at extinguishing solids.
Carbon dioxide (CO2) fire extinguisher
CO2 fire extinguishers are rated for Class B flammable liquid fires. They are thus very good for electrical fires since they are not a conductor (unlike water) and there is no residue. CO2 fire extinguishers are a good choice for offices given the existence of electricity and a large space. CO2 fire extinguishers aren’t to be used in small spaces due to the risk of asphyxiation.
Water mist fire extinguisher
Water mist fire extinguishers are rated for Class A, B, C, and electrical fires so they are very versatile. Water mist extinguishers utilize a very thin mist curtain that reduces oxygen content and thus makes it appropriate for electrical fires as the mist doesn’t conduct electricity the way regular water fire extinguishers do. The water mist fire extinguisher additionally doesn’t create puddles which can be an electrocution hazard. It also has the cooling and soaking effects of water.
Wet chemical fire extinguisher
Wet chemical fire extinguishers come with different ratings and are good for dealing with fat and grease fires in kitchens but may additionally be capable (depending on the model) of tackling Class A and possibly B fires too.
Fire extinguisher types and classes summary
| Extinguisher | Class A fire | Class B fire | Class C fire | Class D fire | Class K fire |
| Water | Yes | No | No | No | No |
| Foam | Yes | Yes | No | No | Yes |
| Dry powder | Yes | Yes | Yes | Yes | No |
| CO2 | No | Yes | No | No | Yes |
| Wet chemical | Yes | No | No | No | Yes |
What does the number on a fire extinguisher mean?
Fire extinguishers include a code comprised of letters and numbers that can be confusing. Specifically, fire extinguishers rated either A or B have ratings that specify their ability to fight that sort of fire.
You may see a fire extinguisher rated as follows and wonder what it means:
1-A:10-B:C
1-A – The first number represents the equivalent in gallons of water that the fire extinguisher offers. 1-A means that the fire extinguisher has enough fire agent equivalent to 1.25 gallons of water. 2-A means it would have the equivalent of 2 x 1.25 = 2.50 gallons of water. And so on.
10-B – For every B, it means that the fire extinguisher can deal with 10 square feet of fire. So a 10B fire extinguisher can handle a 10 square foot fire. A 20B fire extinguisher could handle a 20 square foot fire. And so on.
C – This particular fire extinguisher is also rated to handle a C fire which is unrated for volume or distance. A C fire is one that typically contains aspects of an A and B fire but with the addition of electricity. So a C-rated fire extinguisher contains an additive that doesn’t conduct electricity.
In summary, a 1-A:10-B:C rated fire extinguisher can deal with Class A, B and C fires if the unit is big enough to handle the fire ie. it’s no bigger than 10 square feet.
Fire extinguishers for each area of the home
Two organizations that help to classify fire extinguishers that shed light on what you may need for your home use:
NFPA: The National Fire Protection Association (NFPA
) gives recommendations regarding the number and type of fire extinguishers a home should have.
UL LLC: The UL LLC (formerly known as Underwriters Laboratories) is a safety organization that publishes standards on a wide variety of items including fire extinguishers. You may come across references to their ratings such as UL Listed to 711A which means it’s a fire extinguisher that is rates for residential cooking equipment.
Here are some guidelines for rooms in your house that could use a fire extinguisher.
Kitchen
A UL listed 711A fire extinguisher is specifically designed to handle a fire that could typically occur in a kitchen. Kidde’s RESSP 711A-rated kitchen fire extinguisher is the first one of its kind specifically rated by UL for kitchen use.
The NFPA states that cooking is the leading cause of fires and related injuries in the home yet only 25% of households have a fire extinguisher in the kitchen to handle a fire should one break out.
An extinguisher of this kind would typically have around 2.5 lbs of fire retardant material in the unit on average.
Living room
A UL-rated 2-A:10-B:C fire extinguisher is designed to deal with a fire that could break out in a living room area typically involving wood, fabrics, furnishings, and drapes among other materials.
An extinguisher of this kind would typically have around 4 lbs of fire retardant material in the unit on average.
Garage
For a garage or workshop area, a fire extinguisher with a 3-A:40-B:C rating is one possible choice. It is designed to deal with the types of materials that could catch fire in a garage such as paint, wood, gasoline & electrical equipment among others.
An extinguisher of this kind would typically have around 5.5 lbs of fire retardant material in the unit on average.
Home office
Depending on what your home office entails – are you service-based or are you storing goods – you may look at a fire extinguisher with UL-rating:
1-A:10-B:C – This rating indicates the model is for small fires only.
2-A:10-B:C – This would be good for a sales office, church, assembly hall, classroom and hotel guest area.
3-A:40-B:C – This would be good for a business with light manufacturing, a dining area, an auto showroom, parking garage and storage area.
4-A:60-B:C – This would be good for manufacturing processes involving flammable liquids, boat and vehicle servicing and woodworking businesses.
How to use a fire extinguisher in your home (PASS)
The acronym PASS is used to quickly help people react to a small fire with their personal fire extinguisher when safe to do so:
P: Pull the safety pin on the fire extinguisher
A: Aim the fire extinguisher hose at the base of the fire
S: Squeeze the lever to extinguish the fire
S: Sweep side to side to extinguish the fire
Repeat the last three steps if the fire remains or reignites and it’s safe to do so.
How your local fire station can help with your fire extinguisher questions
Your local fire station might be able to help you in several ways on the issue of fire extinguishers. They may:
- Provide advice to what brand and model of fire extinguisher you need for your specific situation.
- Help you recharge your current fire extinguisher or tell you if you need a new one.
- Refer you to someone who can recharge your fire extinguisher for a fee, typically between $20 and $50 depending on the unit size.
- Help you recycle your old fire extinguisher rather than throwing it out.
Remember: A home fire extinguisher is only to be used for small fires that you feel can be quickly contained. Call the fire department and don’t remain in the house if you’re putting yourself in danger!